Cristobalite and quartz

Cristobalite
CAS Registry Number 14464-46-1

Quartz
CAS Registry Number 14808-60-7

What are they?

Cristobalite and quartz are naturally-occurring minerals. Quartz is found abundantly in many types of rock formations (for example, sand) while cristobalite can be found in the ashes of volcanic eruptions and in a relatively smaller number of rock types limited to specific geographic regions.
Both cristobalite and quartz are commonly used in industrial applications.

The major uses of cristobalite and quartz are in construction-related activities such as road building, sanding of roads in winter, and as a cement additive.
Other uses include the manufacturing of glass fibres, ceramics, rubber and coatings, and as an abrasive.
Cristobalite and quartz are both manufactured in and imported into Canada.

Prior to the assessment, cristobalite and quartz were identified as potential concerns to human health based on their classification by international organizations as substances that were found to cause cancer in humans in occupational settings, and based on a high potential for exposure (not including workplace exposures) to the general population of Canada.
Cristobalite and quartz were not considered to be high priorities for assessment of potential risks to the environment; however, potential environmental effects were also evaluated in this screening assessment.

The general population of Canada may be exposed to cristobalite and quartz through the inhalation of particulate matter containing quartz and cristobalite. Particulate matter may be generated naturally by wind and human activities such as agriculture, construction operations, and vehicle traffic.

Cristobalite and quartz may be released to the environment as a result of natural wind erosion and human activities such as agriculture, construction operations and vehicle traffic.

The Government of Canada has conducted a science-based evaluation of cristobalite and quartz, called a screening assessment.
Screening assessments address potential for harm to the general population (not including workplace exposures) and the environment.
Based on the conclusion of the final screening assessment, cristobalite and quartz are not expected to bioaccumulate in or cause harm to organisms, and the quantities of cristobalite and quartz that may be released to the environment are below the levels expected to cause harm to organisms; therefore, the Government of Canada has concluded that cristobalite and quartz are not entering the environment in a quantity or under conditions that constitute a danger to the environment.
The Government of Canada has also concluded that cristobalite and quartz are not harmful to the health of the general population at current levels of exposure.

Based on the conclusion of the final screening assessment, the Government of Canada proposes that no further action be taken on cristobalite and quartz.
The final screening assessment report was published on June 29, 2013.

The health risks associated with a chemical depend on the hazard (its potential to cause health effects) and the dose (the amount of chemical to which you are exposed). Cristobalite and quartz are not a concern for the environment or human health at current levels of exposure.
As a general precaution, Canadians are reminded to carefully follow safety warnings and directions, including directions to wear personal protective equipment (for example, respiratory protection), when using products containing cristobalite or quartz.
Canadians who handle cristobalite and quartz in the workplace should consult with their occupational health and safety representative about safe handling practices, applicable laws and requirements under the Workplace Hazardous Materials Information System (WHMIS).